implement Fsmodule;include "sys.m";	sys: Sys;include "draw.m";include "sh.m";include "fslib.m";	fsfilter: Fsfilter;	fslib: Fslib;	Report, Value, type2s, quit: import fslib;	Fschan, Fsdata, Entrychan, Entry,	Gatechan, Gatequery, Nilentry, Option,	Next, Down, Skip, Quit: import Fslib; Query: adt {	gate: Gatechan;	stat: Sys->Dir;	mask: int;	cflag: int;	reply: chan of int; 	query: fn(q: self ref Query, d: ref Sys->Dir, name: string, depth: int): int;}; types(): string{	return "xx-pp-ms-us-gs-ts-as-c";} badmod(p: string){	sys->fprint(sys->fildes(2), "fs: size: cannot load %s: %r\n", p);	raise "fail:bad module";} init(){	sys = load Sys Sys->PATH;	fslib = load Fslib Fslib->PATH;	if(fslib == nil)		badmod(Fslib->PATH);	fsfilter = load Fsfilter Fsfilter->PATH;	if(fsfilter == nil)		badmod(Fsfilter->PATH);} run(nil: ref Draw->Context, nil: ref Report,			opts: list of Option, args: list of ref Value): ref Value{	ws := Sys->nulldir;	mask := 0;	gate: ref Value;	cflag := 0;	for(; opts != nil; opts = tl opts){		o := (hd opts).args;		case (hd opts).opt {		'p' =>			gate.discard();			gate = hd o;		'm' =>			ok: int;			m := (hd o).s().i;			(ok, mask, ws.mode) = parsemode(m);			mask &= ~Sys->DMDIR;			if(ok == 0){				sys->fprint(sys->fildes(2), "fs: chstat: bad mode %#q\n", m);				gate.discard();				return nil;			}		'u' =>			ws.uid = (hd o).s().i;		'g' =>			ws.gid = (hd o).s().i;		't' =>			ws.mtime = int (hd o).s().i;		'a' =>			ws.atime = int (hd o).s().i;		'c' =>			cflag++;		}	} 	dst := chan of (Fsdata, chan of int);	p: Gatechan;	if(gate != nil)		p = gate.p().i;	spawn chstatproc((hd args).x().i, dst, p, ws, mask, cflag);	return ref Value.X(dst);} chstatproc(src, dst: Fschan, gate: Gatechan, stat: Sys->Dir, mask: int, cflag: int){	fsfilter->filter(ref Query(gate, stat, mask, cflag, chan of int), src, dst);	if(gate != nil)		gate <-= ((nil, nil, 0), nil);} Query.query(q: self ref Query, d: ref Sys->Dir, name: string, depth: int): int{	c := 1;	if(q.gate != nil){		q.gate <-= ((d, name, depth), q.reply);		c = <-q.reply;	}	if(c){		if(q.cflag){			m := d.mode & 8r700;			d.mode = (d.mode & ~8r77)|(m>>3)|(m>>6);		}		stat := q.stat;		d.mode = (d.mode & ~q.mask) | (stat.mode & q.mask);		if(stat.uid != nil)			d.uid = stat.uid;		if(stat.gid != nil)			d.gid = stat.gid;		if(stat.mtime != ~0)			d.mtime = stat.mtime;		if(stat.atime != ~0)			d.atime = stat.atime;	}	return 1;} # stolen from /appl/cmd/chmod.bUser:	con 8r700;Group:	con 8r070;Other:	con 8r007;All:	con User | Group | Other; Read:	con 8r444;Write:	con 8r222;Exec:	con 8r111;parsemode(spec: string): (int, int, int){	mask := Sys->DMAPPEND | Sys->DMEXCL | Sys->DMDIR | Sys->DMAUTH;loop:	for(i := 0; i < len spec; i++){		case spec[i] {		'u' =>			mask |= User;		'g' =>			mask |= Group;		'o' =>			mask |= Other;		'a' =>			mask |= All;		* =>			break loop;		}	}	if(i == len spec)		return (0, 0, 0);	if(i == 0)		mask |= All; 	op := spec[i++];	if(op != '+' && op != '-' && op != '=')		return (0, 0, 0); 	mode := 0;	for(; i < len spec; i++){		case spec[i]{		'r' =>			mode |= Read;		'w' =>			mode |= Write;		'x' =>			mode |= Exec;		'a' =>			mode |= Sys->DMAPPEND;		'l' =>			mode |= Sys->DMEXCL;		'd' =>			mode |= Sys->DMDIR;		'A' =>			mode |= Sys->DMAUTH;		* =>			return (0, 0, 0);		}	}	if(op == '+' || op == '-')		mask &= mode;	if(op == '-')		mode = ~mode;	return (1, mask, mode);}